*{
    margin: 0;padding: 0;
}
.big{
    background-color: rgb(245, 241, 241);
    display: flex;
    .left{
        width: 80px;
       line-height: 60px;
       text-align: center;
    .btn.active{
        color: red;
        background-color: #ffffff;
        font-weight: bold;
        height: 50px;
        width: 80px;
      }
    }
    .right{
        flex:1;
        flex-wrap: wrap;
        display: flex;
        background-color: #fff;
        .item{
          width: 30%;
          text-align: center;
          margin-top: 15px;
          margin-left: 20px;
          img{
            width: 70%;
          }
        }
      }
}